Caster device



May 25, 1965 J. w. BRIGHAM CASTER DEVICE Filed May 16. 1961 INVE'IV7 'ORJAMES w. BRIGHAM United States Patent 3,l%4,'783 CASTER DEVICE lames W.Brigham, 6744 Brantferd Ave, South Burnaby, British Columbia, (IanadaFiled May 16, 1951, Ser. No. 113,4?7 1 Claim. Cl. 16-18) This inventionrelates to caster devices and particularly to caster devices for usewith furniture intended to be stationed on or moved over floorcoverings, such as carpets and the like.

The most common type of caster used heretofore for supporting furnitureand the like has been the ordinary roller caster. This type of caster,however, whilst providing a satisfactory rolling support has manydrawbacks as a stationary support. The principal drawback of the rollercaster lies in the fact that it has a relatively small bearing area withthe result that when a load is applied thereto the high pressure exertedover the small area creates depressions in the surface of the floors andfloor coverings below the casters. This damage to the floors and floorcoverings is of course greatly aggravated when the article of furnitureor the like is allowed to remain long in any one position. To overcomethese drawbacks, it has been the common practice to provide cups orother rests for insertion between the rollers and the floor or floorcoverings. These cups provide an extended bearing surface on the flooror floor coverings and thus minimize damage thereto. However, these cupshave to be removed when it is desired to move the article supported fromone position to another and then restored when the article is in its newposition.

The present invention seeks to overcome these drawbacks and objects ofthis invention are to provide a simple inexpensive caster device whichenables the article supported to be readily moved from one position toanother and which provides a relatively large bearing surface, thuseliminating or minimizing damage to the floor or floor covering.

In accordance with these objects, the present invention contemplates theprovision of a caster device comprising a casing adapted to be mountedon an article to be supported, said casing having a smooth lowerflooring engaging surface, and a rotatable element journalled in saidcasing and projecting slightly below said lower casing surface throughan opening formed therein into contact with said flooring, saidrotatable element and the lower casing surface forming a substantiallyeven and unbroken bearing surface elfectively supporting an applied loadwhen on a soft flooring, such as a carpet, without unduly disarrangingthe latter and the exposed portion of said rotatable element supportingthe load on a hard flooring, such as a wooden floor, and enabling thearticle to be easily moved over said hard flooring.

Other features which may be included in accordance with this inventionwill be described hereinafter and referred to in the appended claim.

The invention will now be more particularly described in connection withthe accompanying drawings which show examplary embodiments of theinvention, and in which:

FIGURE 1 is a top plan View of one form of the invention,

FIGURE 2 is a side elevation of the device according to FIGURE 1,

FIGURE 3 is an end elevation of the device of FIG- URE 1,

FIGURE 4 is a side elevation of an alternative form of the invention,and

FIGURE 5 is a sectional view taken on the line 55 of FIGURE 4.

3,184,?33 Patented May 25, 1%65 ice Referring to the drawings, thecaster device as shown in FIGURES 1 to 3 comprises a casing generallydesignated 10 rotatably coupled at its upper end to a stem 12 forvertical rotation about said stem. The stem 12 is adapted to be mountedon the bottom of an article, such as a piece of furniture to besupported. Although casing 10 is shown coupled to a pivot, such as stem12, for rotation about a vertical axis, it will be appreciated that ifdesired the casing could be fixedly attached direct to the bottom of thearticle to be supported. The casing 14 includes a lower cup-shapedportion 14 and a body portion 16 having a pair of downwardly inclinedarms 18 and 2t? projecting thereform. The lower ends of arms 18 and 2dextend into the interior of portion 14 and terminate in end flanges 22and 24 which are secured to the inner surface of portion 14. Thecup-shaped portion 14 is formed with a central opening in the form of aslot 26. An axle in the form of a bolt 28 having a roller 36 rotatablymounted thereon is passed through aligned holes in the arms 18 and 2dand secured in position therein by a nut 32. The axle 28 is mounted onarms 18 and 2th in a position so that a small portion of the peripheryof roller 30 projects through the slot 26 in the cup-shaped portion 14.

In use, the caster device is intended be mounted on the bottom of anarticle, such as a piece of furniture, to be supported with the stem 12thereof extending into said article. With the caster thus mounted, themajor portion of the weight of the article is supported by the lowersurface of the cup-shaped portion 14 which forms a relatively large loadbearing surface as compared to the roller which in the present case isonly required to support a small portion of the applied load. FIGURE 2shows the device mounted on the leg 34 of a piece of furniture placed ona carpet 36 having an underlay 37 and as shown a major part of theweight of the article is transmitted to the carpet through thecup-shaped portion 14. In this manner the applied load is more evenlydistributed over the carpet than is the case with the conventionalcasters which due to their small bearing areas damage carpets and floorsby creating depressions therein particularly if allowed to remain forany length of time in one position. Furthermore, the present casterdevice through the roller 38, a portion of which projects below thecup-shaped portion 14, enables the piece of furniture to be readilymoved from one position to another even over a heavy carpet since thelower surface of cup-shaped member 14 glides easily over the carpet whenrolling motion is imparted to roller 39. When the piece of furniture isstationary, its weight is distributed over a large bearing area. Thepresent device thus enables the article supported to be easily movedfrom one position to another and presents a relatively large bearingarea to the floor or floor covering when in a stationary position, thuseliminating or minimizing the possibility of damaging the floor or floorcovering.

In another form of the invention shown in FIGURES 4 and 5, the casterdevice includes a closed casing generally designated 40. Casing 49 is ofsubstantially oval configuration and is formed of upper and lowerinterfitting sections 42 and 44 respectively. Upper section 42 is formedadjacent its lower peripheral edge with a flange 46 having an annulargroove 47 formed in the inner peripheral surface thereof. The upperperipheral edge 4d of lower casing section 44 forms a snap fit withinflange 46 and the two sections are releasably interlocked upon theengagement of the annular ridge 45 formed adjacent the upper peripheraledge of lower section 44 with the groove 47. The upper section 42 ofcasing 40 is, as shown, preferably pivotally connected to a stem 51which is fixedly attached to the article to be supported, but could alsoif desired be directly and fixedly attached to the said article. Thelower section 44- of casing 40 is provided with an opening 5'2 centrallythereof and the upper section 42 is provided with spaced arms 54 and 56depending downwardly therefrom and terminating above opening 52. An axlein the form of a bolt 58 having a roller 66 rotatably mounted therein issupported between arms 54 and 5d and secured in position thereon bymeans of a nut 62. The axle 58 is so positioned that a portion of theroller 60 projects downwardly through the opening 52 in lower section 54of casing 40 into engagement with the floor or floor covering.

In this second embodiment of the invention, the applied load istransmitted to the floor or floor covering over the curved lower surfaceof casing section 44 and through.

the roller till whereby the load is distributed over the relativelylarge bearing surface. Also, with this design the roller issubstantially concealed from sight providing a neat locking, streamlinedand substantially dust-proof unit.

What I claim as my invention is:

A caster device comprising a casing adapted to be rotatably mountedadjacent the bottom of an article to be supported, said casingcomprising a pair of interfitting shells, the upper one of said shellshaving a pair of spaced arms depending downwardly therefrom interiorallythereof and the lower shell forming a flooring engaging surface andbeing formed with an opening centrally thereof, and a roller carryingaxle fixedly connected at each .end to said arms in a positionwhereat aportion of the roller periphery projects slightly downwardly throughsaid opening into contact with the flooring, said roller and the outersurface of said lower shell forming a substantially even and unbrokenbearing surface eifectively supporting an applied load when on asoft'fiooring Without unduly disarranging the latter and the exposedportion of said roller supporting the load on a hard flooring andenabling the articleto be easily moved over said hard flooring.

References ited by the Examiner UNETED STATES PATENTS 635,680 10/99Guinan 16-26 63 6,757 11/99 Carrawayo 888,426 5/08 Legge 16'41 X1,012,040 12/ 11 Means.

DONLEY J. STOCKING, Primary Examiner.

IGSEPH D. SEERS, Examiner.

